Boiler return trap



April 25, 1933. v F|NA 1,906,052

BOILER RETURN TRAP Filed- July 5, 1928 2 Sheets-Sheet 1 16 a a: 7i

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April 25, 1933. v. FINA 1,906,052

BOILER RETURN TRAP Filed July 5, 1928 2 Sheets-Sheet 2 F'zgfi- PatentedApr. 25, 1933 r UNITED STATES PATENT OFFICE 3 vALENrmE FIN-A, OFMILWAUKEE, WISCONSIN, ASSIGNOR TO MILWAUKEE VALVE COMPANY, or MILWAUKEE,WISCONSIN, A CORPORATION WISCONSIN BoILEa RETURN TRAP Application filedJuly 5, 1928. Serial No. 290,550.

This invention relates particularly to return traps especially adaptedfor use with heating system boilers.

In heating systems of the steam vapor and like types, the pressurewithin the return line piping and the boiler is customarily equalized byreturn traps that heretofore have been more or less dependent uponsprings and other unreliable actuating means. It is,therefore, an objectof this invention to provide a return trap of the character describedwhich functions entirely independent of springs or other similaractuating means.

Another obj ect of this invention resides in the provision of animproved valve structure for boiler return traps having gravity actuatedmeans for maintaining the valves in their proper positions.

And a further object is to simplify and generally improve theconstruction of boiler return traps of the character described.

With the above and other objects in view which will appear as thedescription proceeds, my invention resides in the novel construction,combination'and arrangement of parts substantiallyas hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims. I,

In the accompanying drawings,-'I have illustrated one complete exampleof the physical embodiment of my invention constructed according to thebest mode I have so far devised for the. practical application of theprinciples thereof, and in which:

Figure 1 is a transverse, sectional view taken through a returntrape'mbodying my invention, the parts being illustrated with the steamvalve 'closed and the vent valve p r l i V T Figure 2 is anenlarged,side view of the valve actuating mechanism detached from its,supporting structure, parts thereof being broken away and in section;

Figure 3 is an enlarged view similarto Figure 1 of the valves andftheiractuating means in a position opposite of that shown in Figure 1; and

Figure 4 is a cross-sectional view taken through Figure 1 on the planeof the line Referring now more particularly to the accompanyingdrawings, in which like numerals designate like parts throughout theseveral views, 5 designates a fluid receptacle or body havingan inletpipe 6 threaded in an aperture 7 formed in its bottom wallwhich'connects the receptacle with the return line piping of a heatingsystem, not shown, the return water of the system entering thereceptacle in the conventional manner. A flanged cover member 8 issecured over the flanged upper end 9 of the receptacle by cap screws orother like means 10 V and has a steam inlet port 11 connected with'thesupply main of'the heating system, not shown, through a pipe 12. A ventport 13, also formed in the cover member is connected with an air outletvalve, not shown, by a pipe 14.

A boss 15 on the under face of the cover 9 receives the flange 16 of amounting member secured thereto by screws 17 or the like, a suitablegasket being interposed between the boss and flange to provide a fluidtight joint therebetween. A pair of downwardly directed spaced arms 18extend from the flange 16 and have aligned apertures 19 in their outerends through which a rod 20 passes to pivotally mount a valve actuatingmember, designated generally as 21. l

The member 21 is substantially a walking beam having a main cross bar 22through which the pivot 20 passes at a medial point and which isenlarged at two points equi distant from the pivot, as at 23; Each en'-largement 23 is apertured, as at 24, to receive the lower ends of valvestems 25 which are pivotally connectedthereto by rivets or other means26. The upper ends of'the stems are provided with approximately squareenlargements 27 having theirupper ends recessed to receive ball,members. 28 which are held in their recesses by peening over-theadjacent edges 29.

that cooperate with the lower edges of apertures in the flange 16 inalignment with the ports 11 and 13 to selectively close the same, andcounter-bores 31 communicating with the apertures 30 are formed indownwardly projected lugs 32 on the flange 16 to provide guides for theenlargements 27 the corners of which freely slidably engage the walls ofthe counterbores and provide fluid passages therepast. Inasmuch as thevalve stems 25 are connected with the member 21 at points equally spacedfrom its pivotal mounting 20, rocking thereof simultaneously closes onevalve while the other is opened. I

Approximately triangular extensions 33 directed laterally from the endsof the arm 22 of member 21 are connected by three rods 34 substantiallyparallel with member 21 but transversely disposed with respect to thepivot 20. The rods 34 form a cage or trackway for a spherical weight 35which is free to roll from one end of the member 21 to the other for thepurpose to be-later described. One end of the member 21 (the right withrespect to Figures 1 and 4), has an arm 36 extended therefrom in adirection opposite to the end members 33 to lie within the path of theends 37 and 38 of a subtsantially A-shaped trip fork 39.

The fork 39 is freely pivotally mounted at its apex by the rod 20 andcarries a counterbalance weight 40 which is so positioned that when theparts are as shown in Figure 1, the center of gravity of the combinedweight of the fork 39 and the weight 40 is to be right of a verticalline drawn through the pivot 20 and when the parts are as shown inFigure 4, the center of gravity above referred to moves to the left ofthe imaginary line.

The lower arm 41 of the fork 39 has a stud 42 secured therein at amedial point which is slidably received in elongated openings 43 in thesides of a yoke member 44 mounted on the upper end of a guide rod 45 onwhich a float 46 is freely slidable.

The operation of the return trap is simple and positive, as when theheating system with which it is used is operating under a very lowpressure, or under atmospheric pressure only, the trap acts as areceiver and air vent but when the boiler pressure increases the fluidlevel within the trap rises carrying with it the float 46.

As the float 46 rises, it abuts a rounded toe 47 on the end 38 of thefork raising it a distance suflicient to permit the center of gravity ofthe combined weight of the fork and the weight 40 to pass to the left ofthe imaginary line drawn vertically through the pivot 20, the weight 40then quickly moving the fork to its position illustrated in Figure 2. Asthe trip fork moves to this position, the end 38 thereof abuts the lowerside of arm 36 moving the member 21 to close the vent 13 and open thesteam port 11.

The pressure in the boiler and trap is then equalized and the fluidwithin the re ceptacle discharges from the receptacle by gravity andenters the boiler without collecting in the return mains regardless ofthe boiler pressure. The valves are maintained in this position by thespherical weightwhich rolled to its position shown in Figure 3 as themember 21 was moved by the trip fork. The weight 35 is especiallyeffective when the steam valve is closed as it then precludes its beingopened by external pressure.

The elongated openings 43 in the U- shaped member 44 provide the desiredlost motion between the rod 45 and the trip fork so that as the floatrises to tilt the fork no additional weight is imposed which might tendto retard its movement. The valve actuating mechanism is therebysubstantially full floating or in other words unretarded by exteriormeans being entirely actuated by gravity from one position to the other.

As the fluid within the receptacle is discharged, the float drops to thebottom of the trap and abuts a stop 48 secured to the lower end of therod 45 opening the vent valve and closing the steam valve. This actionrepeated as long as there is a differential r in the pressure betweenthe boiler and the return line piping. The lower end of the guide rod 45is suitably guided in an aperture 49 in an arm 50 extended across theaperture 7 in the receptacle bottom.

From the foregoing description, taken in connection with theaccompanying drawings, it will. be readily apparent to those skilled inthe art to which an invention of the character described appertains,that I have provided a return trap for boilers in which the actuatingmeans is positive in operation being entirely independent of springs orother like unreliable means.

lVhat I claim as my invention is:

1. In a return trap, a receptacle having ports in one wall, valves forthe ports, a member within the receptacle connecting the valves wherebyone is open while the other is closed, a guideway carried by the member,a weight movable along the guideway to maintain the valves in eitherposition by gravity, and means including a pivotally connected weightfor moving the member to cause the weight to move along the uideway.

2. In a return trap, a receptacle having ports in one wall, valves forthe ports, a member within the receptacle connecting the valves wherebyone is open while the other is closed, means pivotally mounting themember at a medial point, arms projected from the member, rodsconnecting said arms to form a guideway, a first named weight movablealong the guideway and adapted to maintain the valves in either positionby gravity, and means including a pivotally connected weight for movingthe member about its pivotal mounting to effect a corresponding movementof the valves and the first named weight.

3. In a return trap, a receptacle having ports in one wall, valves forthe ports, a member within the receptacle coordinating the valveswhereby one is closed while the other is open, a guideway carried by themember, a first named weight movable along the guideway and adapted tomain tain the valves in either position, a trip member including apivotally mounted weight, a single means pivotally mounting the membercoordinating the valves and the trip member, and float means for movingthe trip member to effect movement of said member coordinating thevalves, whereby the valves are moved from one position to the other andthe first named weightmoves along its guideway.

4. In a return trap, a supporting member having ports therein, valvesfor the ports, a member within the receptacle coordinating the valvesfor inverse movement whereby one is open while the other is closed, aguideway carried by the member, a first named weight movable along theguideway and adapted to maintain the valves in either position bygravity, a trip member including a pivotally mounted weight, a singlemeans carried by the supporting member for pivotally mounting saidmember coordinating the valves and the trip member cooperating meanscarried by the member coordinating the valves and the trip memberwhereby movement of the trip member is imparted to said member, theweight of the trip member being so distributed with relation to itspivotal mounting as to maintain the same in either of two positions bygravity, and a float for moving the trip member from one position to theother to effect a reversal of the positions of the valves and themovement of the first named weight along the guideway.

5. In a return trap, a receptacle having a pair of ports in one wall, avalve for each of said ports, a member within the receptacle pivotedabout an axis, said member connecting the valves whereby one of saidvalves is opened while the other of said valves is closed, a pluralityof rods carried by the member to form a guideway, a weight movable alongthe guideway and adapted to maintain the valves in either of saidpositions, a frame pivoted about said axis and adapted at the limits ofits movement to move said member from one position to another, a weightconnected to said frame adapted to eflect a snap action to said memberand a float in said receptacle having a lost motion connection with saidframe whereby said float actuates the frame to a member within saidreceptacle pivotally mounted about an axis therein, said member havingmeans to retain a ball for rolling movement thereon, means connectingsaid member with said valves whereby one of said valves is open whilethe other of said valves is closed, a frame pivotally mounted on saidaxis and adapted at the limits of its movement to move said member toactuate said valves, a weight connected to said frame and adapted togive a snap action to said member and a float connected to said frame toeffect movement thereof.

7. In a return trap of the character de scribed, a receptacle having apair of ports in one wall, a valve for each of said ports, a memberwithin said receptacle pivotally mounted about an axis therein, saidmember having means to retain a ball for rolling movement thereon, meansconnecting said member with said valves whereby one of 7 said valves isopen while the other of said valves is closed, a frame pivotally mountedon said axis and adapted at the limits of its movement to move saidmember to actuate said valves, a weight connected to said frame andadapted to give a snap action to said member and a float having a lostmotion connection with said frame whereby action of said valves iscontrolled by the level of water in said receptacle.

In testimony whereof I have hereunto afiixed my signature.

VALENTINE FINA.

